"Great place to raise a family"

My sister-in-law lives here and her husband was also raised here and it has developed over the past several decades. 9th Aveneue is a great location for a family because it's far enough away from the downtown, located near a cute park (Central Park) off of Laurel Ave and close to St Matthew's church. It's not that far to walk to downtown but it will take about 20 minutes.
Draeger's supermarket is nearby at 5th and there's a 24 Hour Fitness at 4th. Downtown is less than a mile if you want to walk it. But there's also plenty of parking available.

"A mix of residential and hip downtown"

I've watched B Street develop over the past five years or so into a quaint shopping mecca competing with the likes of 4th Aveneue in San Mateo. B Street is residential at one end and gradually turns into cute coffee shops, boutiques, and more just as you pass 9th Street and more so as you pass 5th street heading into downtown. The train does go by a block away, but although you can hear it, it seems more like background noise. It's a great location because you can walk to downtown San Mateo from B street and get around easily.

"Not Quite Downtown San Mateo"

The whole street is east of El Camino (facing St Matthew's Church) and includes a medium range residential area, a light industrial area (plant nurseries to commercial rug cleaning), and great worker's cafes (Mexican to American). It is another old neighborhood with mature trees and backs into San Mateo's Central Park for even more charm. As a fan of mixed neighborhoods, this area is more pleasing than the one I grew up in (west of El Camino, homes only, upper middles class). It feels like the potential for amazing discovery is more city-like than suburban on this street.

"Eclectic & Ethnic Shopping Street"

B Street in its entirety (not just South B) has the most interesting and varied shops, restaurants, entertainment options, and is just citified enough to be interesting to singles. There are antique shops, movie theatres, and restaurants serving everything from sushi to papusas. Brew pubs, import stores, coffee houses, ravioli delis, and a couple of restaurants that have valets, all compete for your entertainment dollar. It's a blast, though some parts are funkier than others.

"A blend of residential and business..."

South B Street in San Mateo, CA is a very mainstream street, so to speak, as it is home to many residential zones and as well as commercial businesses (for instance - Lifestyle Management/Personal Concierge, Elite Skin Care, and Nazareth Plaza Dental Group - just to name a few). Serving as a fair blend of the two, South B Street continues at the end of North B Street up until about 6th Avenue where it briefly turns into North Railroad Avenue before turning back into South B Street and ending onto South Boulevard. Another great thing about this area is that Central Park is not that far away if you're into some excellent scenery, it's just a block or two over.

"Visit San Mateo's Central Park."

Right off 9th Avenue is a great place called Central Park. The park has great sport facilities and a modern playground. What makes this park unique is that there is an authentic Japanese Garden and a functioning narrow gauge railroad. This is really a great green space in the middle of a city. The best thing about this park is that it appeals to adults and children.